CVE-2026-47123
CVE-2026-47123 — FreeScout: Agent Impersonation via Missing HMAC Verification on Notification Reply Message-ID Path
FreeScout is a free help desk and shared inbox built with PHP's Laravel framework. Prior to 1.8.220, the email processing pipeline in FreeScout's FetchEmails command has two code paths for identifying agent (user) replies based on In-Reply-To / References headers. The notification reply path (notify-{thread_id}-{user_id}-...) extracts thread_id and user_id directly from the Message-ID without HMAC verification. An external attacker who can spoof the From address of a helpdesk agent can inject messages that FreeScout processes as legitimate agent replies — which are then automatically forwarded to customers via the legitimate SMTP server. This vulnerability is fixed in 1.8.220.
Published Updated Sources: cvelistV5, GitHub_M
Triage
Is it exploited, how likely is exploitation, what does it touch, and how severe do the scoring sources call it.
Exploitation
Unreported
no source claims exploitation
EPSS
0%
chance of exploitation in 30 days
CVSS base
7.5
HIGH
CISA SSVC assessment
Three decision points CISA publishes for the CVEs it assesses · SSVC 2.0.3. A stakeholder decision, not a severity score.
Exploitation
PoC
none · proof-of-concept · active
Automatable
No
can an attacker script all four kill-chain steps
Technical impact
Partial
partial · total control of the vulnerable component
Affected scope
The catalog records vendors and products as separate lists, not pairs, so which product belongs to which vendor is not something this page can say.
Vendors (1)
Products (1)
Every base score collected
Sources score independently and disagree; each row says who scored it and under which version.
| Score | Version | Severity | Expl. | Impact | Source |
|---|---|---|---|---|---|
| 7.5 | CVSS 3.1 | HIGH | — | — | cvelistV5 |
Weakness & attack patterns
- CWE-290
- CWE-345
Attack patterns reported against this CVE. The ATT&CK techniques below are inferred from its weakness class.
- T1134Access Token Manipulation
- T1528Steal Application Access Token
- T1539Steal Web Session Cookie
References
3 on the record
- github.com/freescout-help-desk/freescout/security/advisories/GHSA-6r38-6mcf-2ww3
x_refsource_CONFIRM
- github.com/freescout-help-desk/freescout/commit/d902f19038213c6a376947d269b00440908e88a0
x_refsource_MISC
- vincent.vulcoord.net/score/?state=Not+Scored&year=2026&year=2025&assigned_to=a165dae3-480e-4f7d-bbb8-9b1d78115b69&cve=CVE-2026-47123&analyze=1
exploit
Elsewhere on this site
- freescout help deskevery CVE for this vendor
- CWE-290other pages naming this weakness
Not in any source we poll
Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.
- No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
- No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
- No exploit packet captures, log samples, or incident case IDs supplied.